A growing body of empirical data indicates that survey procedures which require respondents to reveal sensitive information to human interviewers are afflicted by non-trivial reporting biases. Until recently, telephone surveys could not offer a private interview context. A recent advance in telephone survey methods, telephone audio computer-assisted self interviewing (T-ACASI), offers a fully private interview context of telephone survey measurements of AIDS-related and other sensitive behaviors. In a T-ACASI survey, a human interviewer is used to screen and recruit eligible subjects. However, once the subject has been recruited and has completed nonsensitive portions of the survey, the phone call is transferred to the T-ACASI system and computer-controlled, pre-recorded questions are read to the subject. The subject provides responses by pressing keys on a touch-tone telephone. Evidence from a pilot T-ACASI survey of AIDS-related behaviors indicate that use of T-ACASI procedures is feasible and that (1) respondents report feeling more comfortable providing sensitive information about their sexual histories to a T-ACASI system rather than to a human interviewer, and (2) use of T-ACASI appears to reduce the under-reporting bias for survey measurements of sensitive, stigmatized, or illicit behavior. The present application seeks support for a two-stage research project to assess the impact of T-ACASI methodology on survey measurement of AIDS-related and other sensitive behaviors. In Phase 1, the investigators will compare the relative validity and reliability of data provided during a T-ACASI interview to that obtained from a standard telephone interview using a human interviewer in a national probability of adults in the United States. In Phase 2, the investigators will contrast the results obtained from T-ACASI interviewing to results obtained using the considerably more expensive, personal visit survey procedures that afford similar levels of privacy. Specific aims of this research program are the assessment of: 1) the extent, if any to which new T-ACASI technology may increase the validity and reliability of telephone survey measurements of AIDS-related and other sensitive behaviors; 2) the extent to which T-ACASI telephone survey methods may provide a reasonable substitute for more expensive, in-person survey measurement procedures; and 3) the costs and barriers to adoption of this technology (assuming that the technology is found to yield improved measurements). In addition to these basic scientific aims, the proposed research aims for an additional, scientific application. The survey instrument to be used in this research will replicate one used in a major NIH-funded program of telephone surveys of AIDS-related behaviors: the National AIDS Behavioral Survey (NABS) research program. By replicating measurements from these surveys, the investigators aim to be able to make direct assessments of the extent of the biases that may affect these widely-used sources of information on AIDS related behavior in the United States and, if appropriate, make statistical adjustments to account for such bias.